Revert "[RegisterBankInfo] Add methods to get the possible mapping of an

instruction on a register bank. This will be used by the register bank select
pass to assign register banks for generic virtual registers." and the follow-on
commits while I find out a way to fix the win7 bot:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/19882

This reverts commit r265578, r265581, r265584, and r265585.

llvm-svn: 265587